I assume the first limit you would hit is the BIOS int13 one which means 8.5GB.
Its much more likely this PC has a 520mb limit, its only a 386, I know many 486's were limited by this one even. 8.5gb limit is more late 486/early pentium limitation.
Either one however can be overcome easily with a DDO like Ontrack, or find a way to install an additional BOOT-ROM in the system with the XT-IDE BIOS (boot ROM socket on Network Card is common).
If the OP goes SCSI, only REALLY early SCSI cards usually had limits like these, I have SCSI Macs, and PCs with cards dated 1989, that detect and boot 30+GB semi-modern SCSI drives just fine.